1. Field of the Invention
The present invention relates to a waveform observing apparatus for displaying measured data in waveform on a display, and a waveform observing system including an external computer.
2. Description of the Background Art
There are known waveform observing apparatuses for storing measured data on temperature and pressure of equipment on a factory production line, and also displaying a waveform on a display, such as a logger, or displaying a potential difference in waveform, such as an oscilloscope. The measured data on temperatures and pressure historically used to be written in waveform on rolled paper (chart), but with the development of electronic equipment, a waveform observing apparatus that displays a waveform by use of a display in place of paper is currently in wide use.
The waveform observing apparatus is capable of displaying in a display section a constantly varying measured value, namely a time-series waveform, while storing measured data captured from a thermocouple or the like into a memory mounted to the waveform observing apparatus. For example, Japanese Patent Application Laid-Open No. H7-114349 and Japanese Patent Application Laid-Open No. 2002-82133 each disclose a waveform observing apparatus having a display with a touch panel. Japanese Patent Application Laid-Open No. H7-114349 proposes that, by a user touching a function key displayed in a display section, a function designated by the function key displayed in the display section is executed. Japanese Patent Application Laid-Open No. 2002-82133 displays that, while a displayed waveform is observed, an operation of inputting a comment or a marking by pen-input is performed using a pen-input touch screen.
There has been a request as the need for the waveform observing apparatus to rapidly enlarge and reduce a displayed waveform even when the waveform observing apparatus repeatedly stops and starts collection of measured data, while leaving measured data before stoppage on the screen of the display section. In the case of responding to this first request, it is desired that, when collection of measured data is once stopped and then resumed, a boundary between the stoppage and the resuming be seen in a display on the screen. Apart from this, however, there has been a problem in that displacement of a handwritten comment occurs with the enlargement and reduction.
This displacement is described with reference to FIG. 29. FIG. 29A shows a display state when a handwritten comment is written. FIG. 29B shows a display state when an enlarged display is made in a time-axial, namely lateral, direction. FIG. 29C shows a display state when a reduced display is made in the time-axial direction.
Further, in ordinary cases, editing and the like are performed using an external computer, and with a difference in number of pixels and size between the external computer and the display of the waveform observing apparatus, the foregoing problem of displacement of the handwritten comment is apt to occur.